Cellular signaling Flashcards
Compartments of the body and compostiton
Intra / Extra
Intracellular (Inside Cells):
40% K (Potasium)
Extracellular (Interstitial):
20% Transcellular fluid
NA (Sodium)high
NaCl NaHCO3
Equilibrium State
Steady State
Equilibrium - NO transfer of a particular substance or energy from one compartment to the other
Steady State: does not change with time – the amount or concentration of a substance in a compartment is constant
Uses Energy to maintain the state
GAP Junctions
AUTOCRINE
PARACRINE
NERVOUS
Endocrine
Gap junctions: adjacent plasma membranes - intercellular communication or transfer of low molecular- weight substances (made of connexin)
Autocrine: substance secreted by a cell acts back on surface receptors of the same cell
Paracrine: substance secreted by a cell acts on adjacent cells
Nervous: substance released by an axon terminal that influences a target neuron or cell
Endocrine: substance secreted by a cell that is distributed by the blood

GAP Junctions
cells including cardiac and smooth muscle. (Contract in synsitium)
6 x connexin form a half channel called a connexon.

Signal Transduction
Plasma Membrane Receptors
On plasma membrane or In Cell
(LIGAND) first messengers from transmitting cells can convert their info to a second messenger within the target cell
First messengers include peptides, protein hormones, growth factors, steroids, ions, metabolic products, gases, light
Second messengers include cAMP, cGMP, IP3, calcium, and DAG

G protein-Coupled Receptors
Trimeric GTP-binding regulatory proteins
Respond to first messengers
Proteins, small peptides, amino acids, fatty acid
derivatives
Binding of ligand results in conformational change that allows the receptor to associate with a trimeric G protein in the inner leaflet of the plasma membrane
This association activates the G protein which dissociates from the receptor and transmits the signal to the effector enzyme or ion channel
Basic Functions of the GI Tract

Peritoneal Cavity
Omentum
Mesentary
Greater sack of Omentum - Gravitates to infection (Apendix to prevent the spread of infection
Mesentary- The access created by the Pariatal peritoneam for Art Veins and Nerves to Small intestine, Holds coils of intestine in place

RetroPerineal
(Behind peritonium)
Organs
Access for SX from Behing Ribs

Arteries of Abdomen
T8 inf Vena cava
T12 DIAphram
L4 Bifurcation of Aorta
Cecelia SMS Renzo Both the IM and AA

Wall of GI tract
Inner - Circle
Outer -Long
Messenteric Plexis
Closed Viseral peritoneum
Muscularis Mucosa

GI tract innervation
NA - Threshold / CA L-type Spike
Uniteric - Syncitium
Messenteric Plexes - Cells of CAJAL - Pace Maker
NA/K Atp ase

Enteric Nervous system
Extension of CNS
Independent
VAGUS N Parasympathetic / Sensory

Patterns of GI Motillity
Propulsion - Peristalsis
Tritiration -Antrum
Mixing

GUT Reflexes
Gastroenteric
- Gastroileal
- Gastrocolic
- Rectoanal - Puborectalis Msc

Salavary Gland Secretions
Carbohydrate + Lipid breakdown start in the mouth
Inc PH with CL-shift antiporter for HCO3(into lumen)
Amylase
Lingual Lipase

Gastric Secretion
PH<3 ihibits Gastrin
Parietal Cells- HCL/ Intrinsic Factor
Chief Cells. - Gastric Lipase Pepsinogen
HCL - Pepsinogen to PEPSIN
G-Cells - Gastrin
H2 Histamine - Incr HCL
Older Px - Decreased B12 (By intrinsic in Ileum) Causes Dementia

ACID Production in Stomach
OMEPRAZOLE
Protein Pump Inhibitors
Overuse - Clostridium Difficle Infec
Pariental Cells
Special adaptation - ALCALINE TIDE Interstitial Fluid. Protect from high Acid
H / K ATPase ACID Produced
CL shift Alcaline tide

Regulation of Stomach ACID
ACH - Para(Muscarinic) ATROPINE
Histamine (Pyloric glands) - H2 - ZANTAC / PEPSID
Parietal cells (Para) Protein in stroma
OMEPRAZOLE - H/K ATPase Proton Pump inhibitor
Block H Exretion

3 Phases Of Acid Stimulation
Stim Parietal Cells Stomach
Intestine - protein Digestion Products
Cephalic(smell) - Para Vagus / Ach Gastrin
Gastic(distension) - Enteric Vago-Vagal - ACH Gastrin
Intestinal - Amino Acids in blood - Amino Acids

Superior Mesenteric Vessels
Just anterior to Duodenum
Most of Pancreas and Duodenum
Retro Peritoneal

Pancreatic Secretions
Neutralize PH Chyme - enzmes to work
Duct cells: CL shift
Cl into for HCO3
H to blood + ACID TIDE (Protect against alkaline)
NA to lumen H2O follow ISOTONICITY
Acinar cells - Pro-enzymes activated by trypsin
Na / Cl

CFTR
Cystic fibrosis Transmembrane Conductance Reg
Cl out of cell to feul HCO3 exchanger
Uses ATP
Morbidity Lung infections

Regulation Of
Pancreatic Secretions
Seritonin
CCK - Trypsin

Functions of the Liver
Nutrient Stores - GLYCOGEN
Metabolic Conversions
CYTOCHROME P450 Enzyme System
Grapefruit juice decreases activity Statins
ITO Cell - Main store of retinal Esters in liver

ITO CELLS

Portal Hypertension
Venous obstruction , Occlusion
Asites
Splemomegaly
Hemroids
Eosophical Varicies
Caput Madusa

Biliary Tree / Gall Bladder
CCK - Contraction Blasser
Open Sphincter Of Oddi

Bilirubin
Jaundice
Ex Neonates UV light Break down Biliruben / Exessive breakdown of RBC / In utero more RBC Dt Low PO2

Regulation of Bile production
CCK
Secritin

GALLSTONES
Clinical
Px starts taking statins - (Excess cholesterol has to te removed)

Digestion
Carbohydrates


Digestion
PROTEINS

Double Bonded Lipid
Ex OMEGAS

Lipid Digestion
Lingual Lipase
Acid Lipase
Pancreactic Lipase
Micelle Structure moste Stable

Absorption of Vinamins And Iron
A D E K, Stored in cells

Endocrine Organs

Feedback Regulation Hormones
Mostly NEG feedback
LH hormone the exception, POS feedback LH surge just before ovulation

Steroids

Polypetide and Protein Hormone production
Cleaved into subunits
ACTH - MSH
Corticosteroids - Melanin stim Hormone

Pituitary Gland
Anterior (Epithelial cells) - Tropic
Posterior( Medial emminance of CN Tissue)

Hypothalamic Pituitary axis
Post Pituitary Hormone Made by Hypothalamus
SECRETED by Post Pituatry
Oxytocin
ADH Vasopressin

Hypothalamic releasing hormones

Anterior Pituitary Hormones

Posterior Pituitary Hormone

ACTH Adenocorticotropic Hormone
ACTH + TRH(thyrotropin)
Cercadian Rythm release
Feedback only to Reticularis and Fasiclata
NOT Glomerulosa where only Aldosterone is made.

Thyroid Gland:
T4 converted to T3 by Target cells
Bind to Tg(Thyroglobulin) in CALOID
Dietary Iodine important
THS stimulates reuptake of Tg and release from same cell

Reverse T3

Thyroid Hormone functions

Goiter

Growth Hormone
GH stimulates IGF 1 Insulin like Growth factor 1
Mitogenic factor mediates effects of growth Hormone
Too Much - Acromegaly
Too Little - Proportional Dwarfism

Adrenal Glands
Cortex (GLUCOCORTICOIDS): G - Aldosteroen
F - Cortisol
R - Androgens
Mudulla - Cathicholamines

Adrenal Gland Cortex Hormone sythesis
Addisons
No feedback ACTH
MSH
Rate limmiting step
11 B hydroxylase Deficient Women
Backflow - Inc Androgens Verilization
Serious Reduced Cortisol
Angiotension 2

Aldosterone
LOW BP

Glucocorticoids
Gives the brain what it needs
Hormone sensitve lipase

Endocrine Pancreas
4 types of cells

Insulin Structure
Better insulin responce to ORAL than IV
Incretin Efecct
SULFONY DRUGS effect

CALCIUM Regulation
Calcitonin
Parathyroid Hormone - Vit D (Calcifarol pathway in gut for absorption)

Vitamin D
Parathyroid
Activation of Mature Vit D
Facilitate the absorption of CA
by Ca binding protein

Osteoporosis
Estrogen effect
protect bone - increase Kidney and Intestinal uptake

Functions of the Kidney
Renin
Eurithropoiten
Acid Base Balance
Degrade insulin and Parathroid hormone
Na - H2O follows

Body fluid Composition
42
14 / 28
10.5/3.5L plasma 25%

Kidney function
Renal Clearance

Glomerular Filtration Rate
GFR
110-125mm/min
Most accurate - INULIN
Inulin Clearance ratio
Daily practice : Endogenous creatin clearance

Endogenous Creatine Clearance Rate
Constantly cleared, high value, slower clearance

Substances not found in Urine (uria)
Fasting blood glucose diabetic 127 mg%
Threshold 180mg% - 200 before spilling into blood
Phenylketoria - Test newborn for enzyme
Cant bread down Phenylealamine to Thyrocine
newborm test / food lable warnings

Renal bloodflow 20% of Cardiac output
Autoregulation of flow
Myogenic mechahisn
Tubulaoglomeric feedback

Determinants of GFR

Proximal Convulated tubule
Large amount of Reabsorption
Acetazolamide
Na / H Pump inactivated
Na Stay in lumen H2O follow excreted in Urine

Loop of Henle
Furosemide (Assending Salts)
Blocks transporter for reabsorption CL K Na
HypoKalemia dt Duretic
Decending Only H20 leaves

Distal Convulated Tubule
Thiazides
Impermeable to H2O unless - Aldosterone ADH
Na Ca pump interstitial side blocked
Ca Na3 pump (CA gradient created) that get upregulated by Parathyroid hormone to add Ca to the blood.
Large channel on lumen side thaCa enters

Cortical Collecting Duct
Principal - Secrete K
K out side with smalle elec Potential DiFF
LOW BP - Adosterone Upregulates Na / H2O follows

Intercallated Cells - Acid Base
H K ATPase
More H pumped out the higher K
HyperKalemia

Urinary Concentration and Dilution
2 counter current processes
Countercurrent Multipliers Loops of henle / Set up gradient
Countercurrent exchangers Vasa Recta / Prevents wash out


Urea in Concentration Mechanism

Dilute Urine ADH levels LOW

Concentrated Urine ADH levels HIGH

Diabetes INSIPIDUS
Polyuria

Potasium Balance
K
Risk in Diabetic Px recieving Insulin
Hypokalemia
Insulin - uptake of K

Emesis
Vometting
xtracellular fluid Volume contraction
H - loss
HCO3 increase Alkaline shift
Bigger issue - Ventilation + More HCO3 uptake

Juxtaglomerular Apparatus
Macula Densa
RENIN
RENIN Secretion
- Beta Adernergic stimulation SYMP
- Reduced Renal Perfusion pressure
* *Detected By JG cells** - Decreased NaCl reabsorption by Macula Densa It Reduction in GFR

Renin
Angiotension
Aldosterone (Principal cell)


Urinary Tract
Micturition
Detruser
Internal Sphincter
Para Symp S 2/3/4

Male Reproductive system
Testosterone - testes
Lydig cells
Sertoli Cells
Seminal vesicle - Prostaglandins + Alkaline

Hormone Regulation Male
FSH
LH
GnRH
Testosterone

Erection - Parasymp Viagra
Ejaculation - Symp

Oogenesis
Produces Haploid daughter cells

Ovarian Cycle
Zona pellucida
Granulosa cells - Corpus luthium (maintain)
Theca Interna
Antrum - Estrodiol

Menstral Cycle
Variation 1st half
Estrogen / Progesterone
LH surge ovulation
Corpus Luteun

Uterine Cycle
1) Menses
2) Proliferative
3) Sectratory
4) Ischemic / Estrogen + Progesterone

Menopause
Decr Estrogen Incr FSH
Parathyroid
Heart attack / Estrogen Vaso-dialator

Fertalization
Day 8

Hormonal levels during Pregnancy

Lactogenesis
Colostrum
Prolactin
Oxytocin
Reduces - LH / FSH

Oral contraception

Morning After Pills
RU 486
PlanB a dose Progestin Levonorgestel
BRACA 1 Breast cancer
